Electric switch



J. ANDERSON ELECTRIC SWITCH 2 SheetsSheet 1 Filed Dec.- 14, 1934 a H1 a m: a f m mfiO iIE 1 m m I 3 w L Z l m nliw f g! A.@ r 5E hnml FE Fm Oct. 27, 1936. J ANDERSON 2,058,656

ELECTRIC SWITCH Filed Dec. 14, 1954 2 Sheets-Sheet 2 IIIIEIIIIIHHIIIHHUI IIHIIHIIIIHHIIH TUHJIJHIHYJIUHF l atented Oct. 27, 1936 PATENT OFFICE 2,058,656 ELECTRIC SWITCH James Anderson, Perry Barr, Birmingham, England Application December 14, 1934;, Serial No. 757,576 In Great Britain October 17, 1934 2 l ims- This invention relates to electric switches or circuit breakers of the kind in which are suppressors are combined with the contacts, the suppressors being of the kind comprising a pile of 5 spaced plates between which a radial magnetic field is formed, and through or into which the movable contact moves into and out of engagement with the fixed contact.

The object of the present invention is to effect 10 improvements in the arc suppressor.

The invention comprises the combinationwith a pile of spaced plates having a hole formed through it, of a contact secured in one end of the hole, a contact movable through the other end of the hole, and a tube of insulating material mounted in the hole and adapted to accommodate the contacts, the tube having formed in one side of it a longitudinal slot through which the arc can escape to the spaces between the 20 plates.

The invention also comprises a movable contact having the greater part of its length enclosed by insulating material.

The invention further comprises the combina- 525 tion with the plates of spacing rings made from insulating material and adapted to enclose the spaces between the plates.

Further the invention comprises an improved --arc suppressor constructed as hereinafter de- 230 scribed.

In the two accompanying sheets of explanatory .,drawings:

Figure 1 is a side elevation with part in sec- -tion showing an electric switch or circuit breaker 35 provided with a pair of arc suppressors in accordance with this invention.

Figure 2 is a vertical section, Figure 3 an elevation and Figure 4 a cross section of one of the arc suppressors.

40 Figure 3 is a side elevation of the movable contact.

The switch. shown in Figure 1, comprises an upper cross member a from which are suspended a pair of arc suppressors, each containing a fixed 45 contact I). There is also suspended from the part a a central rod on which can slide a tube at provided at its lower end with a cross bar e carrying a pair of movable contacts J. Each movable contact is in the form of a stem supported 50 on a spring g and enclosed for the greater part by a sleeve h of insulating material leaving the upper end of the stem exposed. The closing and opening of the circuit or circuits controlled by the switch is effected by moving the contacts 1 55 into and out of engagement with the contacts 1).

Each arc suppressor comprises a pile of spaced plates 2' of non-magnetic material. These are spaced apart by rings 7' of insulating material which also enclose the spaces between the plates. Through a central hole in the pile of plates is inserted an iron rod 10 forming the core of an electromagnet, the winding 1 of which is carried at the upper end of the rod. The rod is enclosed by a sleeve m of insulating material. The flux from the core extends radially across the spaces 1-" between the plates, and the return path is pro vided by iron rods 11 and an iron top plate 0, The rods n are enclosed by insulating sleeves p and they serve also to hold the rings and plates together. 15

Parallel with the core there is formed in the pile of plates a hole to accommodate the fixed and. movable contacts, and this hole is lined by a tube q of insulating material having a slot 1" formed along one side of it. Within the upper end of the tube q is secured the fixed contact b, and the movable contact 1 is adapted to slide into and out of the tube. Preferably a small annular space is provided between the outer surface of the fixed contact and the inner surface of the tube. The length of the fixed contact may be varied, but preferably it is such that it extends across several of the spaces between the plates.

The arrangement above described is such that when the contacts I), are separated, the are formed between them passes through the slot in the tube into the spaces between the plates, where it is given a rotary motion about the axis of the magnet core. In the event of the are performing more than one complete rotation it strikes against the closed side of the tube where it is deflected around one side or the other of the tube and is prevented from joining up again with either contact.

When the arc is formed one end can travel along the fixed contact into the spaces between the upper plates, but movement along the movable contact is restricted by the insulating sleeve surrounding that contact. The rate at which the arc divides between the plates adjacent to the movable contact depends on the rate of separation of the contacts.

By this invention the arc suppressing capacity of apparatus of the kind specified is improved in a very simple and convenient manner.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:-

1. An arc suppressor of the kind specified for an electric switch or circuit breaker, comprising the combination of a pile of non-magnetic plates arranged in spaced relationship and provided with registering apertures which are spaced from the peripheries of the plates so as to form a hole passing through the pile, an electromagnet core passing through another hole in the pile of plates in parallel relationship with the first-mentioned hole, spacing means interposed between the plates but leaving annular spaces therebetween and around the core, a one-piece tube of insulating material passing through the first-mentioned hole, a fixed contact mounted in one end of the tube, the said tube having formed in one side of it a longitudinal slot through which the arc can escape to the annular spaces between the plates and around the core, a contact movable through the other end of the tube, and a sleeve of insulating material on the movable contact arranged to leave only the inner end of the contact exposed, substantially as described.

2. An arc suppressor of the kind specified for an electric switch or circuit breaker, comprising the combination of a pile of non-magnetic plates arranged in spaced relationship and provided with registering apertures which are spaced from the peripheries of the plates so as to form a hole passing through the pile, an electromagnet core passing through another hole in the pile of plates in parallel relationship with the first-mentioned hole, a. sleeve of insulating material enclosing the core, insulating spacing rings interposed between the plates and surrounding the spaces therebe tween, the inner surfaces of the rings and the outer surface of the sleeve forming the inner and outer boundaries of annular spaces between the plates, a one-piece tube of insulating material passing through the first-mentioned hole, a fixed contact of smaller diameter than the tube mounted in one end of the latter, the said tube having formed in one side of it a longitudinal slot through which the arc can escape to the annular spaces between the plates, a contact movable through the other end of the said tube, and a sleeve of insulating material on the movable contact arranged to leave only the inner end of the contact exposed, substantially as described.

JAMES ANDERSON. 

